Production of condensation products from hydrogen sulphide and acetylene



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Patented Apr. 25, 1939 srres PRODUCTIQN OF C(DNDENSATHZEN FD- UCTS FRQMROGEN SEILK BKK DE AND ACETYLENE Walter Beppe 021- ll: J benlndustriethe-Main, Goy

end Fritz Nicolai, Ludwigshotcue, Germany, eseignore to ll. G. For-Aktlengesellschedt, Fre-ort-om-= The present invention relates to theproduction of condensation products from hydrogen sulphide andacetylene.

It is well known to lead acetylene or geese contuining acetylenetogether with volatile sulphur. compounds or with hydrogen sulphide, ifdesired with the addition of oxygen, at elevated temperatures over solidcatalysts, as for example especiolly metals of the iron group, or theiroxygen containing compounds preferably admixed with hydrates, such asbauxite. By that process, there is formed a mixture of differentproducts consisting mainly of thlophene, ethylthiophene, ethylmercapten,and diethylsulphide.

We have now found that valuable and more uniform condensation productsfrom hydrogen sulphide and acetylene are obtained in e, very simplemanner and with good yields by causing acetylene to act on hydrogensulphide in the presence of liquid solvents, at room temperature oradvantageously at elevated temperatures, soy up to 250 0., and ifdesired with the addition of catelysts. Pure acetylene or acetylenediluted with inert gases, such as nitrogen, they be employed. Assuitable solvents may he mentioned, for example, polyhydric alcohols andtheir others still containing free hydroxyl groups, such as mono-, diandtri-ethylene glycol, propylene glycol, tlimethylene glycol, l.3-butyleneglycol, glycerol, polyglycercls and diethylene glycol monoethyl ether.

Metal sulphides such as sulphides and polysulphides of the alkalimetals, slimline earth metals, ammonia. and the heavy metals areeminently suitable as catalysts either when added as such or formed insitu from compounds or salts of metals and ammonia, which are convertedinto sulphides by the action of hydrogen sulphide, as for instance thesuits of copper, iron or nickel.

Depending on whether the acetylene is allowed to act under pressure ondissolved hydrogen sulphide or whether at mixture of acetylene and hydrogen sulphide is led through a solvent of high boiling point in whicha catalyst is dissolved, different reaction products are obtained.

(A) For example if acetylene be allowed to act under pressure at from 60to 100 C. on hydrogen sulphide in an aqueous solution of potassiumhydrosulphide, polymerization products of thicacetaldehyde, especiallythe alphe-trithloaldehyde, are mainly obtained. The same product isobtained by employing dioxane instead of water.

(13) If, on the other hand, hydrogen sulphide be led in admixture withacetylene through a solvent of high boiling point in which a. small (Cl.tdil tltlt l amount of potassium hydrosulphide hes been dissolved es ecdtelyst, ethyl rnercepteu, vinyl ethyl sulphide or ethane dithioldlethyl ether or mixtures of these three products are obtained dependingon the proportions employed.

The course of the reaction can he explained by assuming that at firstthe unknown vinyl mercepten is formed from equlxnoleculer proportions ofacetylene and hydrogen sulphide. in the first case (4%) this vinylmercepten changes into mono thioaceteldehyde, with which it is isomeric.By reason of the foot that monothioeceteldehyde is very unstable endreadily polymerizes, alphatrithloeceteldehyde is mainly obtained es there action product.

In the second case (B) the primarily termed vinyl mercepten is reducedby e. second molecular proportion of hydrogen sulphide into ethylmercepten (the sulphur thus formed being partly used up for theformation of polysulplzides). The ethyl mercepten is then converted bythe excess acetylene into ethyl vinyl sulphide. The letter 7 odds on. efurther molecule of merc'epten with the formeticn of ethane dithioldiethyl ether.

The course of the reactions is shctm in. the following equations: (Aonzcu+u=s=om=ousu on cn-sH- co$c11s omens a c:ep H-SE H-SH-HHgSCHPCHi-SH-FS CEyCHsrBH+CHECH=CHaCHrS-CE=CH3 CEyCHrSCH=CHg+CHr-CHrSH=CHrGETS-CH9 CHQ-CHZ-BCHT The following examples willfmther lhustrete howour present invention may be carried out in practicebut the invention is not restricted to these perticuler examples. Theparts are by weight.

Example A if acetylene be caused to act at too under a, pressure of from10 to atmospheres on an aqueous solution of hydrogen sulphide containing200 parts of hydrogen sulphide to 2'56 ports of water and in wluch 10ports of potassium hydrosulphlde have been dissolved, there is obtainedafter u reaction period of 12 hours an absorption of acetylene of 120parts. The brown oily reaction product consists mainly ofalpha-trithioeldehyde melting at 101 C.

The same product is obtained by employing dioxane es the' solvent forthe hydrogen sulphide instead of water. When working without theemployment of potassium hydrosulphlde as catalyst, alpha-trlthioaldehydeis also obtained, but

the absorption of acetylene is slower.

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, Example B A mixture of equal parts by volume of hydrogen sulphide andacetylene is led at a speed of 44 litres per hour through a verticaliron tube of action liquid, the reaction product obtained after workingfor 40 hours is 505 grams of ethyl mercaptan and 81 grams of vinyl ethylsulphide having a boiling point of 91 C.

By employing a gas mixture consisting of from 85 to 90 per cent byvolume of acetylene and from 15 to 10 per cent of hydrogen sulphide, amixture is obtained consisting of about '7 per cent of ethyl mercaptan,27 per cent of vinyl ethyl sulphide and 64 per cent of ethane dithioldiethyl ether.

What we claim is:

1. The process of producing condensation products from hydrogen sulphideand acetylene which comprises reacting acetylene with hydrogen sulphidein the presence of an aliphatic, watersoluble, liquid solvent selectedfrom the group consisting of polyhydric alcohols and their etherscontaining at least one free hydroxyl group and in the presence of ametal sulphide catalyst.

2. A process as claimed in claim 1, wherein the reaction is carried outin the presence of the therein defined solvent and a catalysu'a sulphideselected from the class consisting oi alkali metal sulphides andammonium sulphides.

3. The process of producing condensation products from hydrogen sulphideand acetyene which comprises leading a mixture of acetylene and hydrogensulphide through an aliphatic, watersoluble, liquid solvent selectedfrom the group consisting of polyhydric alcohols and their etherscontaining at least one free hydroxyl group, in which solvent there isdissolved a catalyst comprising a metal sulphide.

4. The process of producing condensation products from hydrogen sulphideand acetylene which comprises reacting acetylene with hydrogen sulphidein the presence of a water-soluble, symmetrical hydroxy aliphatic etherand in the presence of a metal sulphide catalyst.

5. The process of producing condensation products from hydrogen sulphideand acetylene which comprises reacting acetylene with hydrogen sulphidein the presence 01 diethylene glycol and in the presenceof a metalsulphide catalyst.

6. The process of producing condensation products from hydrogen sulphideand acetylene which comprises reacting acetylene with hydrogen sulphidein the presence of an aliphatic water soluble liquid solvent selectedfrom the group consisting of polyhydric alcohols and their etherscontaining at least one free hydroxyl group and in the presence of acatalyst comprising an alkali metal hydrosulphide.

7. The process of producing condensation products from hydrogen sulphideand acetylene which comprises reacting acetylene with hydrogen sulphidein the presence of an aliphatic water soluble liquid solvent selectedfrom the group consisting of polyhydric alcohols and their etherscontaining at least one free hydroxy group in the presence of a catalystcomprising ammonium hydrosulphide.

WALTER REPPE. FRITZ NICOMI.

